German Patent Application No. 196 26 576 describes a fuel injector having a choke-like narrowing in the area of the magnet armature. The fuel may be fed in such a manner that it flows through the choke-like narrowing with a flow component directed away from the injection orifice. This may cause an at least partially compensating counterforce to be exerted on the valve needle or on the armature which may be non-positively connected to the valve needle.
The fuel injector described in the above-cited document may involve a complicated construction, which may entail considerable effort in manufacturing the components.
Moreover, it may not be possible to optimize the closing times in the fuel injector described above by targeted use of the fuel back pressure acting on the armature, so that the opening times of the fuel injector may also need improvement, since the restoring spring may need to possess a strong closing force in order to seal the fuel injector against the pressure of the combustion chamber.
Conventional fuel injectors may be provided with spiral flutes or swirl boreholes in the region of the metering point. The choking of the fuel flow in the area of these flutes or swirl boreholes may result in a force component acting on the valve needle in the direction of closure. This may adversely affect the valve behavior.